Brush holder



F. W. MCCLOSKEY BRUSH HOLDER March 30,19%;a m 1,578,539

Filed June 24, 1924 WITNESSES: INVENTOR g MM Y Weder/ck h/. 005k@ ATTRNEY Patented Mar. 30,

UNITED STATES 1518.539. PATENT orifice.

FREDERICK W. MCCLOSKEY, OF EDGEVOOD, PENNSYLVANA, ASSIGNOR TO WESTING- HOUSE ELECTRIC & MANUFACTURING COMPANY, A CORPORATION OF PENNSYL- VANIA.

nnnsn: HOLDER.

T 0 all flo/20m t may concern.'

Be it known that I, FREDERICK lV. Mc- CLosKnr, a subject of the King of Great Britain, and a resident of Edgewood, in the county of Alleeheny and State of Pennsylvania, have invented a new and Auseful improvement in Brush Holders, of which the following is a specification.

My invention relatesfto dynamo-electric machines and it has particular relation to a totally inclosed brush holder construction for preventing carbon side wear in machines employing ventilation by means of air drawn from outside the machine frame.

The problem of carbon sie-.e wear has be come quite a serious difficulty, particularly in the operation of railway motors in cities where there is a large quantity of sand, particularly cities at or near the coast. ln some instances, the brushes have actually worn half-way through, on one side,.due to sand or grit, before they were removed from the motor, and it was found that the end wear on the brushes was slight. It was at once evident that if some means could be defsigned to prevent the carbon sine wear, the

destruction of the commutator and the danger of a flash-over could be avoided and the life of the brushes could be increased many fold. Extensive tests in service have demonstrated conclusively that the protection ofbrushes against grit eliminates the side wear as a factor in brush life. According to my present invention, lprovide a dynamo-electric machine havinga construction wherein the ventilating air is drawn over the current-collecting device as usual, but wherein the brush holders are totally inclosed, so as to protect the brushes and the spring mechanism of each holder from contact with the girt-laden ventilating air. Each brush holder is provided with an opening in its top to provide access to the brush box, and said opening is normally closed by a removable cap member. A separate handle member is provided for the brush holder, whereby the cap may be easily removed and whereby the spring finger bearing on the top of the brush may be raised by attaching the handle member as an eX- tension on the end of the spring linger. In prior designs of brush holders, wherein the top of the brush box was left open, it was necessary to leave the brush holder open also at the bottom of the compartment containing the spring mechanism, in order to prevent the'accummulation of dust and grit which would clog up the spring. According to Vmy invention, since no dust or grit is admitted, it is possible to totally inclose the bottom of the brush holder casing thereby protecting the spring from arcs in case of flash-overs on the commutator cylinder. l

lilith the foregoing and other objects in view, my invention relates to the combinations and details of construction hereinafter described and claimed and illustrated inthe accompanyingdrawing, wherein l Figure l is a longitudinal sectional view showing the general ventilating scheme of a direct-current r ilway motor embodying my invention,

Fig. 2 is a detailed end elevation, partly in section, showing my improved brush holder, and f Fig. 3 is a perspective view of the detachable handle member thereof.

ln the accompanying drawing,`my invention is shown-as being applied to a directcurrent railway motor comprising a stator or field member l and a rotor or armature member 2. The stator member is provided with suitable supports carrying brush holders 3 in operative relation to a communtator cylinder 4 mounted on the rotor or armature member 2. A fan member 5 on the rear end of the armature member provides ventiltion for the motor as indicated by the arrows. Any suitable ventilating system may be utilized and no further description thereof is necessary. Y

The brush holder 3 to which my invention more particularly relates comprises a housing member 6 having a' compartment 7 for the spring mechanism and a brush bo-X for carrying a brush 9. The front and rear walls 10 and 1l of the brush bon are pro vided with recesses l2 and 13, respectively, for receiving the end of the laterally extending spring arm lllof the spring mechanism which may be of any suitable or usual construction, preferably comprising a spiral spring member 15.

The brush-holder housing 6 is provided with an opening in the top thereof immediately to the rear of the recess 13 in the rear wall ll of the brush box 10 and the remainder of the housing is totally inclosed. A. housing extension 18 is provided adjacent to the recesses 12 in the front Wall 10 of the brush boi; for receiving the end of the spring arm 1d.

The front and side Walls of the housing extension 18 extend to the same height as the side Walls of the brush boX 10 to provide a fiat surface which may be totally covered by a removably mounted cap member 21. In the form of embodiment of my invention shown in the drawing, the cap member 21 is pivotally mounted on the housing extension 18 and is held in operative position bv means of spring clips 22. The top of the cap member carries a suitable perforated lug 23 Which may be utilized for the purpose of lifting off the cap member to gain access to the brush box. The brush holder carries the usual supporting brackets 25 and terminal lugs 26 for the flexible lead-in conductors.

The provision of the housing extension 18 surrounding the front end of the spring arm makes it quite diflicult to lift the spring arm in order to remove the brush, and l have devised a novel removable handle member or spring-arm extension 2'? comprisingv a straight iever portion 2S carrying a bent sheet-metal clip 29 providing a socket 80 on one side of the lever member at a point removed from the end 31 of the lever meinber, said socket being `open towards said end and closed at the other end. To remove the brush, the spring extension erin 27 is first raised from contact with the broth 9 by inserting the end 31 of the lever membeil into the housing extension i8, a l' cated in dotted lines in Fig. 2, and pryn g the spring extension arm up nntil the spr arm is in alinement with the lever n at which rtime the lever member is pushed forward to engage the end of the spring member in the soclet 30, whereby the lever member becomes a rigid extension tie spring arm and the latter may be easily lifted to permit removal of the brush TheV rear end of the lever member is provided With a. hook 32 terminating in a re duced extension 33 adapted to engage the perforation in the lug 23 on the top of the cap member 21 to facilitate the removal thereof.

1rWhile l have shown my invention in a preferred form, it is obvious that many changes may be made in the details of con` struction and embodiment thereof vr hout departing fron this principles and smy invention. ,i desire.y therefore, t the appended claims shall be accorded the broadest construction commensurate with the language thereof, When read in the iignt of the prior art.

I claim as my inventioni l. A brush holder for eiectric machines comprising an open-topped housing containing a brush box and a iatera-lly extending spring-pressed for the brush, and a cap member removably elosingthe top of the housing.

2. A brush holder for holding a brush in contact With a current-collecting device of an electric machine, comprising a housing enclosed on its side, end and bottom Walls and having an opening in its top Wall, and a cap member removably closing said opening, said holder containing a brush box and a spi l spring mechanism for operatively supporting a brush.

A brush holder for electric machines comprising a housing containing a spring arm mechanism for engagingv the top of a brush and a brush box having its rear Wall recessed to receive a` portion of said springarm mechanism, said housing being open, at its top, behind said recess in the rear Wall of the brnsh box, whereby said spring mechanism may be raised to provide access to brush bor, and a cap member removably closing the tops of the brush bof; and the opening in the topof the housing.

d. A brush holder for electric machines coi ,Y housing containing a springarm mechanism for engaging the top of a brash, brush box having its front and rear Walls recessed to receive Va portion of said spring-arm mechanism, and an opentopped hone-,ng extension enei sing a space around the recess eifing t e 5 n a, the front and side Walls of said honsi extension rising to the same height the side Walls of said brush box.

A brush holder for electric machines comp honsing containing a springarm mechanism for engaging the top of a brush, a brush boa having its front and rear Walls recessed to receive a portion of said spring-arm mechanism, an open-topped housing ext ion enclosing space around the recess in said front v-:all for receiving the end of said spring-arm mechanism, the front and side Walls of said housing extenrising to the same height as the side Wails of said brush bon, said housing being open, at its top, behind said recess in the rear Wall of the brush boia, whereby said spring mechanism may be raised to provide access to said brnsh bol', and a cap member removably closing the tops of the honsing eatension and lrish boxy and the opening in the top of the housing.

in testimony whereof, have hereunto snbscribed my naine this 11th day of June.

i REDERCK Vif. MGCLOSKEY,

t ivall for re- 1 

